Telephone-transmitter



(No Model.) 2 Sheets-Sheet 1.

J. W. BONTA.

TELEPHONETRANSMITTBR.

No. 352,178. PatentedN0v.9,1886.

WITNESSES: INVENTOR/I al g.

A TTORNE Y N. Pzrzns rum-m my, Wahinginn. n. c.

(No Model.)

2 Sheets-Sheet 2. J. W. BONTA. TELEPHONE TRANSMITTER.

Patnted' Nov. 9, 1886.

INVENTOR,

WITNESSES.- flay/ A TTORNEY N PETERS. Phololikhognphor. Wnshingmn, D. Q

U ITED STATES PATENT O FICE.

JAMES w. nonrn, or PHILADELPHIA, PENNSYLVANIA.

.TELEPHONE-TR ANS M ITTE R.

FIPECIPICATION forming part of Letters Patent No. 352,178, dated November 9,1886.

Application filed March 11, 1886.

.To aZZ whom it may concern.-

Be it known thatLJnMEs W. BONTA, a citizen of the United States, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, have invented certain new and useful Improvements in Telephonic Transmitters, of which the following is a specification, reference being had therein to the accompanying drawings, wherein Figure 1 is a vertical section, partly in elevation, of a telephonic transmitter embodytrode, platform, and plate, havingin cross section modified form of groove.

My invention has relation to atelephonic transmitter of the form wherein the diaphragm has a fixed electrode for contact with a loose ball or electrode supported upon an inclined plate or table having mechanism for adjusting its inclination to vary the initial contactpressure between the electrodes; and it has for its object to provide a fixed inclined table adapted to beelevatedor depressed, and, if desired, moved toward or away from the diaphragm for varying the contact-pressure of the electrodes without disturbing or altering the inclination of the table.

My invention accordingly consists of the combination, construction, and arrangement of parts, as hereinafter described and claimed.

A represents a transmitter box or case having hinged door or front a, provided with mouth-piece a. To the door is suitably secured adiaphragm, B, having a fixed electrode, b, preferably made of carbon.

0 is a right-angled bracket, having in its vertical limb a slot, 0, through which passes a set-screw, c, by means of which the bracket is secured to door a, and is adjusted up and down within box. A. The top of bracket 0 is preferably provided with dovetail or other suitably-formed ways or guides, 0 in which slides the foot or stem d of an inclined platform, D, which is firmly held in place on Serial No. 194,803. (No model.)

a slot, (1 in foot d.

Upon the platform D rests a carbon block or plate E,held in positionby set-screws e. (Seen more plainly'in Fig. 3.) JIhe'plate E has preferably a longitudinal groove, 6, which may illustrated in Fig. 4, or a double groove, or two grooves of differentwidths, to providetwo ridges, edges, or tracks, e for the loose electrode or ball F to rest and move upon, and have two or more contacting-points with said plate, as indicated more plainly in Fig. 3.

By adjusting screw 0 the bracket 0, and consequently the platform D, plate or block E, and carbon ball F are elevated or depressed to throw a more or less mass or weight of the electrode b, and thereby vary the initial contact-pressure of the electrodes, and as the platform D has no tilting motion the said contactpressure is regulated-without varying the inclination of plate E or platform D. By adjusting the set-screw d the platform and plate are adjustable to and from the diaphragm after being raised or lowered by the adjustment first above described. Y

The use'of the foregoing double adjustment for platform D andplateEor, in other words, theirup-and-down and to-and-fro movementsadmit of a finer variation of the initial contact-pressure of the electrodes than could be attained if only an up-and-downgadjustnlent is used 5 but if desired, however, the to-andfro adjustment may be dispensed with, as shown in Fig. 2, in which case the bracket and platform are secured together or are in one piece. I

Instead of using the slot and screw devices shown in Figs. 1, 3, swiveled screws engaging with threaded openings in fixed lugs may be substituted, as indicated in Fig. 5.

Any suitable inductorium, I, may be employed, the primary, 1, of whichincludes the diaphragm-electrode, ball F, plate E, and battery 3, and the secondary, 2, forms part of the line.

I do not broadly claim in this application means for vertically adjusting without altering the inclination of the table, as that forms the subject-matter of a separate application ball F above the axial line of the diaphragm bracket C by set-screw d, which passes through be a single groove angular in cross-section, as

filed on even date with this and numbered 7 \Vhat I claim is 1. Inatelephonic transmitter, the combination of adiaphragm having a fixed electrode, a vertically-sliding inclined platform or plate, and a loose ball or electrode resting on said plate in contact with the fixed electrode, substantially as shown and described.

2. The combination of adiaphragm having a fixed electrode, a loose or ball electrode, a vertical moving platform for the ball, and adjusting mechanism for vertically raising and lowering the ball and platform without varying the inclination of the latter, substantially as shown and described.

3. The combination, with case A, of diaphragm B, having a fixed electrode, Z), the vertically-adjustable bracket 0, adjustable plat form D, having carbon-plate and loose ball or electrode F, substantially as shown and described.

4. The combination of diaphragm B, having fixed electrode, the loose electrode F, and the grooved carbon-plate D, having two or more edges or tracks for contact with the ball, substantially as shown and described.

5. In a telephonic transmitter, the grooved carbon-plate having parallel tracks or edges,

as and for the purpose set forth.

6. The combination of a diaphragm, aloose ball or electrode, an inclined table, E, and adjusting mechanism for raising and lowering the table without varying its inclination, substantially as set forth.

In testimony whereof I affix my signature, in presence of two witnesses.

J AMES XV. BONTA.

\Vitnesses:

S. J. VAN STAVOREN, CHAS. F. VAN HORN. 

